We have previously described the purification and partial characterization of a new
pancreatic cancer-associated
antigen, a
pancreatic cancer-associated
mucin expressing CA19-9, CA50, Span-1,
sialyl SSEA-1, and Dupan-2. This study describes the clinical evaluation of various assay systems for this
antigen which depend on measuring respective serum levels. Elevated levels of
antigen were detected in the sera from both patients with malignant and non-malignant diseases. However, elevated serum levels of CA19-9 and Lewisa and Lewisb
epitopes on moieties were restricted to pancreatic and
biliary tract cancers, although adequate sensitivity was not attained. Coordinate evaluation of these three markers improved the sensitivity to some extent without loss of specificity for the diagnosis of pancreatic and
biliary tract cancers, because of the heterogeneity of the coexpression of these
epitopes. We developed additional assay systems with a combination of this
antigen and two
lectins (Bauhinia purpurea (BPA) and Vicia villosa (VVA)). Elevated levels of BPA- and VVA-reactive
antigens were detected in 41% and 31%, respectively, of
pancreatic cancer sera samples. Few patients with
chronic pancreatitis had an elevated serum level of either
antigen, and higher elevated levels of these markers were restricted to the sera of patients with
malignancies. Our results suggest that this
antigen is found in the sera of patients with various conditions and in the sera of normal subjects but that
antigens bearing CA19-9 or Lewisa or Lewisb
epitopes and an altered
carbohydrate structure recognized by BPA and VVA
lectins are preferentially present in the sera of patients with pancreatic and other
malignancies.